The power and effectiveness of hypnosis is bound in scientific evidence and unlike New Age therapies which rely on belief, hypnosis has been shown to be completely effective on even the most skeptical of clients.
Hypnosis relies on the psychological malleability of an individual which is not connected to their belief in the power of hypnosis. Often, people who believe whole heartedly in what hypnosis can achieve and who want to change are completely unable to achieve trance state, it has nothing to do with willingness or belief and everything to do with capability.
Conversely, individuals who are completely skeptical about the hypnotic process and its ability to make changes can be dramatically influenced by the hypnotic state.
An individuals ability to enter trance and be affected by hypnosis is an inbuilt mechanism (like eye colour or handedness) and is not influenced by will or belief. A low susceptibility cannot be changed by wishing and a high susceptibility cannot be changed by concentration and self-control.
You either can or cannot be hypnotised. You will be influenced to a certain degree, whether you want it or not. What you believe and hope for has little to do with the reality of hypnotic process and it is a hard-wired physiological limit that doesn’t change significantly over time.
Before you embark on using hypnosis try to get an understanding of where you or your clients fit on the scale so that you can ensure that you get the best results from the hypnosis session.